Embodiments of the present disclosure relate to a fast steering mirror, and more particularly to methods and systems to calibrate fast steering mirrors. Such fast steering mirrors may be deployed in a sensor or video system associated with a vehicle, a vessel or an aircraft, for example.
Fast steering mirror systems are known, and provide the backbone of some conventional sensors and/or video systems. For some applications, the fast steering mirror needs to be calibrated. Calibration of high order errors requires a large number of measurements, which is a time consuming task when using traditional measurement systems. Traditional measurement systems are prone to systematic errors caused by changes in environmental conditions. Many calibration systems use a theodolite, which is an autocollimator mounted on a gimbal to calibrate angular travel. One limitation associated with the theodolite is that it is only as accurate as an encoder associated with the gimbal. Moreover, theodolite measurements are time consuming to perform, making this approach difficult to use for higher order correction. Laser trackers are also used to calibrate fast steering mirrors since they can be automated, which is good for high order correction. Measurement resolution and measurement range compete against one another, which limit the range and resolution required to calibrate fast steering mirrors.